Method for the determination of a receiver for location information

ABSTRACT

The invention relates to a method for distinguishing between LOCATION REPORT messages to avoid ambiguities. Therefore, a value of an information element of request type is returned by a radio network controller, depending on an intended receiver of the location information. A control node receiving the information element value analyses said value and determines the receiver depending on the result of said analysis.

FIELD OF INVENTION

The invention relates to a method for determining the receiver oflocation information sent by an access network node. The inventionfurther relates to a method for a control node and a method for anaccess network node for executing the invention, a mobile servicesswitching centre and a GPRS support node adapted to executing saidmethod and software adapted to control a control node and a softwareadapted to control an access network node in a way that the nodesexecute the invented method.

DESCRIPTION OF PRIOR ART

Location services are defined for example in 3GPP (third GenerationPartnership project) specifications TS22.071, version 3.2.0, publishedJanuary 2000. In general, location services deliver a service that isrelated to the location of user equipment. To provide a locationservice, a service provider depends on the knowledge of the location ofuser equipment.

FIG. 1 depicts the architectures standardised in 3GPP TS 23.271, version5.0.0, published October 2001. The architecture comprises two GatewayMobile Location centres GMLC1, GMLC2, connected to core network nodesMSC, SGSN. One of the gateway mobile location centres GMLC1 is connectedto an external location service client LCSC, to a home location serverMSC or SGSN and a home subscriber server HLR or HSS. The other gatewaymobile location centre GMLC2 is connected to an external public landmobile network PLMN. The control nodes MSC, SGSN are connected to thehome location server HLR and a home subscriber server HSS, as well as toa radio access network UMTS Radio Access node SRNC. The radio accessnode is a radio network controller SRNC and is further connected to anode B and a further radio network controller RNC. The node B serves auser equipment UE.

The Gateway Mobile Location Centres GMLC1, GMLC2 contain functionalityrequired to support location services. In one network, there may be morethan one Gateway Mobile Location Centre.

The Gateway Mobile Location Centre GMLC1, GMLC2 is the first node anexternal location services in a mobile network. The Gateway MobileLocation Centre GMLC1, GMLC2 may request routing information from thehome location register HLR or the home subscriber server HSS. Afterperforming registration authorisation, it sends positioning requests tomobile services switching centre MSC or the serving GPRS (General PacketRadio Service) support node SGSN and receives final location estimatesfrom the corresponding entity.

The home location register HLR and the home subscriber server HSScontain location services subscription data and routing information. Fora roaming mobile subscriber, home location register/home subscriberserver HLR/HSS may be in a different mobile network from the one he iscurrently roaming into. The location services subscription data aretransferred from the home location register/home subscriber serverHLR/HSS to the mobile services switching centre MSC or the serving GPRSsupport node SGSN during the location update procedure.

Location services subscription data include a privacy profile containingthe privacy classes for which location of the target subscriber ispermitted. Each privacy class is treated as a distinct supplementaryservice with its own supplementary service code.

The mobile services switching centre MSC and the serving GPRS supportnode SGSN contain the functionality responsible for the user's locationservices subscription and privacy. The location services functions ofmobile services switching centre MSC and the serving GPRS support nodeSGSN are also related to charging and billing, location servicesco-ordination of all location requests, authorisation and authenticationof the positioning requests received from the Gateway Mobile LocationCentre GMLC1, GMLC2.

The serving radio network controller SRNC provides, among the others,the serving mobile location client functionality that means it is thenode in which the user equipment location information is calculated.

The location services system provides the opportunity of requesting thelocation of the mobile user terminals from an external location servicesclient (Mobile Terminating Location Request=MT-LR), the location fromthe terminal itself (Mobile Originating Location Request=MO-LR) and theauto-induced location from the network (Network Induced LocationRequest=NI-LR).

The node B, the radio network controller SRNC, RNC and the userequipment UE are not explained in more detail.

FIG. 2 gives an example of a circuit switched, mobile terminating,location request.

In this figure the access network nodes node B, serving radio networkcontroller SRNC and radio network controller RNC are combined in theradio access network RAN. An external entity EE sends a location requestLRQ to a mobile service switching centre MSC to gain locationinformation of a user equipment UE. The mobile services switching centreMSC executes paging, authentication and ciphering with the userequipment UE. These steps may be redundant in the case of a busy userequipment.

In the depicted case of UMTS (Universal Mobile TelecommunicationsSystem) access, the Location Request is sent from the mobile servicesswitching centre MSC to the radio access network RAN by means of RANAP(Radio Access Network Application Protocol) LOCATION_REPORTING_CONTROLmessage LRC. The steps performed to execute a calculation of a positionof the user equipment UE depend on proprietary positioning methods. Theresult of the calculations is received in RANAP LOCATION_REPORT messageLR. The location request result is sent from the mobile servicesswitching centre MSC to the external entity EE in aLOCATION_REQUEST_RESULT message LRR.

LOCATION_REPORTING_CONTROL and LOCATION_REPORT RANAP messages are usedfor both Location Services and other mobile services switching centreMSC or serving GPRS support node functions SGSN, not related toPositioning, asking to report upon change of Service Area. Ifpositioning is requested, the serving radio access controller shallreport on a per request base, if reporting upon change of Service Areais requested, the serving radio access controller shall report wheneverthe user equipment UE moves between Service Areas.

It is a shortcoming of the system as described in 3GPP TS 23.271,version 5.0.0 and in 3GPP TS 25.413, version 4.2.0, that it is notpossible to distinguish a LOCATION_REPORT message received as a resultof a Service Area change from the same message received as an answer onan external location request. In the case that a service area change isreported by a LOCATION_REPORT message while a LOCATION_REPORT message isexpected as an answer to a LOCATION_REPORTING_CONTROL message thatdemands an immediate response, there is no mechanism to distinguishbetween the respective LOCATION_REPORT messages.

It is object of the invention to introduce a system that can distinguishbetween LOCATION_REPORT messages, sent as an answer on different events.

SUMMARY OF THE INVENTION

In order to distinguish between LOCATION_REPORT messages, a component ofthe LOCATION_REPORT message, the request type information element, isanalyzed according to specific parameters. Analysis of the request typecauses either the location information to be sent immediately or atrigger to be set that determines the appropriate receiver of thelocation information. The appropriate receiver includes an externalentity or a network node.

Further advantageous is that an identification of the request type isincluded in the LOCATION_REPORT message only if the location informationis intended for a network node according to claim 4. By this, thehandling of LOCATION_REPORT message is simplified significantly.

The control nodes, that is the GPRS support node SGSN and the mobileservices switching centre MSC comprise means for analysing a value of arequest type information element filed of a LOCATION_REPORT message andmeans for determining a receiver of location information. These meanscan be implemented by hardware, for example as a logic circuit or bysoftware, for example a software module, or both.

BRIEF DESCRIPTION OF THE DRAWINGS

The following figures show:

FIG. 1: depicts an architecture for the support of location services asstate of the art, (state of the art)

FIG. 2: depicts a signal flow for a location request as state of theart, (state of the art)

FIG. 3: depicts a flow diagram of the invented method,

FIG. 4: depicts a further flow diagram of the invented method, and

FIG. 5: depicts a further flow diagram of the invented method.

DETAILED DESCRIPTION OF EMBODIMENTS

In the following the invention is described in more detail by means ofembodiments and figures.

The invention uses the already existing information element request typeof the LOCATION_REPORT message for determining the recipient of alocation information. The determination is executed in a control node.In the case that the request is a packet switched location request it isexecuted by a SGSN, in the case that it is a circuit switched request itis executed by a mobile services switching centre MSC.

FIG. 3 depicts a flow chart of the invented method. In a first step, acontrol node sends a LOCATION_REPORTING_CONTROL message to a radionetwork controller. This message comprises an information elementrequest type that identifies the type of request. The type of request isidentified for example that the radio access network is requested tosend location information in a LOCATION_REPORT message at a change ofservice area by a user equipment or as a direct response on theLOCATION_REPORTING_CONTROL message.

In a next step, the radio network controller receives theLOCATION_REPORTING_CONTROL message. It analyses it whether the value ofthe information element request type indicates to send a LOCATION_REPORTmessage immediately, or not. If a LOCATION_REPORT message is requiredimmediately, the radio network controller determines the location of auser equipment and sends the location information together with therequest type value received in the LOCATION_REPORTING_CONTROL message tothe core network node. If the LOCATION_REPORT message is required aftera certain trigger event, in this example a change of service area by theuser equipment, the radio network controller sets the respective triggerevent and monitors, whether the user equipment changes the service area.If so, the radio network controller detects this trigger event,determines the location information of the user equipment and sends ittogether with the received request type value to the control node.

The control node receives the LOCATION_REPORT message including therequest type. It checks whether the request type value indicated animmediate response. If so, the location information is intended for anexternal entity and the control node sends it to said external entity.If not, the information is used internal of the network.

FIG. 4 depicts another flow chart of an alternative of the inventedmethod to the implementation as described by FIG. 3. In a first step, acontrol node sends a LOCATION_REPORTING_CONTROL message to a radionetwork controller. This message comprises an information elementrequest type that identifies the type of request. The type of request isidentified for example that the radio access network is requested tosend location information in a LOCATION_REPORT message at a change ofservice area by a user equipment or as a direct response on theLOCATION_REPORTING_CONTROL message.

In a next step, the radio network controller receives theLOCATION_REPORTING_CONTROL message. It analyses it whether the value ofthe information element request type indicates to send a response, thatis a LOCATION_REPORT message, immediately, or not. If a LOCATION_REPORTmessage is required immediately, the radio network controller determinesthe location of a user equipment and sends the location informationtogether with the request type value received in theLOCATION_REPORTING_CONTROL message to the core network node. If theLOCATION_REPORT message is required after a certain trigger event, inthis example a change of service area by the user equipment, the radionetwork controller sets the respective trigger. The radio networkcontroller monitors, whether the user equipment changes the servicearea. If so, the radio network controller detects this trigger,determines the location information of the user equipment and sends itto the control node. In this embodiment, the lack of the request typeinformation element value in the LOCATION_REPORT message, indicates thatthe message is to be used network internal.

The control node receives the LOCATION_REPORT message including therequest type. It checks whether a request type value is returned. If so,the location information is intended for an external entity and thecontrol node sends it to said external entity. If not, the informationis used network internal.

FIG. 4 depicts an embodiment of the invention by means of a flow chart,wherein the determining is handled vice versa to the embodiment of FIG.3. In the embodiment of FIG. 3, a request type value has been returnedin the case that the location information is to be used networkinternal. In the embodiment of FIG. 4 the request type value isreturned, when the location information is to be forwarded to anexternal entity.

Request type values indicating that an immediate response is requiredare for example: “Request of current location” or “Request of current orlast known location”.

The invention further relates to software stored on a computer readablemedium or in a form that can be loaded into a memory of a computingdevice. A computing device is for example a control node or a controlnode server that executes a stored program.

The invention claimed is:
 1. Method for determining a receiver forlocation information in a communication system for mobiletelecommunications adapted to operating according to Universal MobileTelecommunications Systems specifications, wherein the system comprisesat least one access network, at least one control node adapted to handlelocation service requests and an interface to at least one externalentity that uses location information, and wherein the following stepsare performed by the control node: sending a LOCATION_REPORTING_CONTROLmessage comprising a request type information element for indicating thetype of location request to at least one radio network controller of theaccess network, receiving a LOCATION_REPORT message comprising alocation information and a request type information element, analysing avalue of the request type information element received in theLOCATION_REPORT, determining a receiver of the location information sentin the LOCATION_REPORT based on the result of the analysis.
 2. Methodaccording to claim 1, wherein the request type information element sentin the LOCATION_REPORT message always comprises an identification of thetype of location request.
 3. Method according to claim 1, whereinrequest type information element sent in the LOCATION_REPORT messagecomprises an identification of the type of location request in the casethat the location information is intended for a network node.
 4. Methodaccording to claim 3, wherein the control node is a mobile servicesswitching centre.
 5. Method according to claim 3, wherein the controlnode is a serving general packet radio service support node.
 6. Themethod according to claim 1 further comprising the step of, upondetermining the receiver is external to the network, immediately sendingthe LOCATION_REPORT message to the determined receiver.
 7. The methodaccording to claim 6 further comprising the step of, upon determiningthe receiver is internal to the network, sending the LOCATION_REPORTmessage upon a specified trigger event.
 8. Method for answering aLOCATION_REPORTING_CONTROL message for a radio network controller, themethod comprising the following steps: receiving from a control node aLOCATION_REPORTING_CONTROL message, comprising a request typeinformation element for indicating the type of location request,determining the requested location information, and sending aLOCATION_REPORT message comprising the location information and therequest type information element wherein a value in the request typeinformation element depends on an intended receiver of the locationinformation, the value of the request type information element beinganalyzed by the radio network controller and a receiver of the locationinformation is determined based on the result of the analysis.
 9. Acontrol node, for handling location service requests, in a UniversalMobile Telecommunication System (UMTS) mobile communication system,wherein the control node is configured to: send aLOCATION_REPORTING_CONTROL message comprising a request type informationelement for indicating the type of location request to at least oneradio network controller of an access network of the communicationsystem; receive a LOCATION_REPORT message comprising a locationinformation and a request type information element; analyze a value ofthe request type information element received in the LOCATION_REPORTmessage; and determine a receiver of the location information sent inthe LOCATION_REPORT based on the result of the analysis.